Structure, sulfatide binding properties, and inhibition of platelet aggregation by a disabled-2 protein-derived peptide

J Biol Chem. 2012 Nov 2;287(45):37691-702. doi: 10.1074/jbc.M112.385609. Epub 2012 Sep 13.

Abstract

Disabled-2 (Dab2) targets membranes and triggers a wide range of biological events, including endocytosis and platelet aggregation. Dab2, through its phosphotyrosine-binding (PTB) domain, inhibits platelet aggregation by competing with fibrinogen for α(IIb)β(3) integrin receptor binding. We have recently shown that the N-terminal region, including the PTB domain (N-PTB), drives Dab2 to the platelet membrane surface by binding to sulfatides through two sulfatide-binding motifs, modulating the extent of platelet aggregation. The three-dimensional structure of a Dab2-derived peptide encompassing the sulfatide-binding motifs has been determined in dodecylphosphocholine micelles using NMR spectroscopy. Dab2 sulfatide-binding motif contains two helices when embedded in micelles, reversibly binds to sulfatides with moderate affinity, lies parallel to the micelle surface, and when added to a platelet mixture, reduces the number and size of sulfatide-induced aggregates. Overall, our findings identify and structurally characterize a minimal region in Dab2 that modulates platelet homotypic interactions, all of which provide the foundation for rational design of a new generation of anti-aggregatory low-molecular mass molecules for therapeutic purposes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / chemistry*
  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism
  • Amino Acid Motifs
  • Amino Acid Sequence
  • Apoptosis Regulatory Proteins
  • Binding Sites
  • Circular Dichroism
  • Humans
  • Micelles
  • Models, Molecular
  • Molecular Sequence Data
  • Peptides / chemistry*
  • Peptides / metabolism
  • Peptides / pharmacology*
  • Phosphorylcholine / analogs & derivatives
  • Phosphorylcholine / chemistry
  • Platelet Adhesiveness / drug effects
  • Platelet Aggregation / drug effects*
  • Protein Binding
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Sequence Homology, Amino Acid
  • Sulfoglycosphingolipids / chemistry*
  • Sulfoglycosphingolipids / metabolism
  • Surface Plasmon Resonance
  • Tumor Suppressor Proteins / chemistry*
  • Tumor Suppressor Proteins / genetics
  • Tumor Suppressor Proteins / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Apoptosis Regulatory Proteins
  • DAB2 protein, human
  • Micelles
  • Peptides
  • Sulfoglycosphingolipids
  • Tumor Suppressor Proteins
  • Phosphorylcholine
  • dodecylphosphocholine

Associated data

  • PDB/2LSW